Known gripper constructions usually have a clamp member adapted to be secured on a pivotal gripper shaft in a predetermined position and the sheet gripper is usually mounted and guided resiliently on the clamp member with the sheet gripper spring force acting from the clamp member relative to a sheet gripper stop. The clamp member of the known sheet grippers, however, is generally expensive and complex to manufacture because of the adaptor required for the drive shaft. Usually, the sheet grippers can be removed only when the gripper shaft is removed from the printing machine. This removal of the gripper shaft requires considerable time and leads to particularly high costs for assembly or adjustment of the sheet grippers, particularly on a change thereof.
German utility model No. 6 608 544 discloses a sheet gripper which solves the problem of so constructing a gripper provided with pivoting levers that are rotatable with respect to stops which are stationary relative to the gripper holder, thus obviating the disadvantages of the known constructions. With respect to perfect register during sheet transfer, this gripper is also said to have advantages that were hitherto obtainable only with gripper arms of the kind in which the parts cooperating with the stops carry out a traversing movement with respect to the stops during closing and opening, without the disadvantages of a large travel during the gripper opening and closing movement.